<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <title>Title</title>
</head>
<body>
<script>
    // Object.is(value1, value2)  判断两个值是否是相同的值
    
    // console.log(Object.is(1, '1')); // true

    console.log(+0 === -0); // true
    console.log(Object.is(+0, -0)); // false
    console.log(Object.is(NaN, NaN)); // true
</script>
</body>
</html>
